This application seeks $110,000 for an "Applied Biosystems Model 471A-02 Gas-phase Protein Peptide Sequencer with Micro-gradient PTH Analysis System" to be installed in the Protein Sequence Facility at the University of Pittsburgh. The instrument will replace the less sensitive and outmoded Beckman Model 890M liquid-phase (spinning cup) instrument currently in place at this facility. The PI has been the Director of the Sequence Facility since mid-1985. The PI's experience in protein sequence work dates from his post-doctoral period in the laboratory of Hans Jornvall. Thus, he is well acquainted with protein sequence determination methodologies. He has been PHS funded (by NIAAA) at the R01 level since 1987, and is a past recipient of both pre- and post-doctoral funding also from NIAAA. The instrumentation in the protein sequencing laboratory was purchased in 1983 through a PHS shared instrumentation award, and the PI was recruited to supervise and develop the Facility. Since that time, spinning-cup type protein sequencers have become outmoded if not virtually obsolete. Gas phase sequencers offer superiority in economy and ease of operation, much greater sensitivity, and the capacity to operate on samples prepared rapidly and reliably by electroblotting to polyvinylidine difluoride, derivatized glass or other inert, proprietary membranes from polyacrylamide electrophoresis gels. Until recently this was only an analytical technique. Summaries are provided of 22 PHS-funded projects which will benefit from access to this type to protein sequencing technology at the University of Pittsburgh.